Panel lamp socket of insulation having opening engaging resilient fingers



April 10, 1956 R C WOOFTER 2,741,747

PANEL LAMP S OCKET OF INSULATION HAVING OPENING ENGAGING RESILIEZNTFINGERS Filed March 11, 1954 2 Sheets-Sheet l 3e 40 42 2O 6 3o 4 iJ J Iso I i I i I; 5 if I 50 I 76 38 78 I8 64 74 Q 2Q 54 58 60 R D IN!'ENTOR.

0 C, wooffer 66 Fig.2 62

His Attorney April 1956 R. c. WOOFTER PANEL LAMP SOCKET OF INSULATIONHAVING OPENING ENGAGING RESILIENT FINGERS 2 Sheets-Sheet 2 Filed March11, 1954 o2 INVENTOR.

Robert C. Wooffer HIS Attorney United States Patent 7' PANEL LAMP SOCKETOF INSULATION OPENING ENGAGING RESILIENT FINGERS Robert C. Woofter,Cortland, Ohio, assignor to General Motors Corporation, Detroit, Mich, acorporation of Delaware Application March 11, 1954, Serial No. 415,553

9 Claims. (Cl. 339-128) This invention relates to lamp sockets and, moreparticularly, to lamp sockets adapted to be supported on the dash of anautomotive vehicle, and adapted to receive light bulbs which serve toilluminate various instruments such as ammeters, pressuare gauges ofvarious sorts and other generally similar indicating devices.

Some indicating lamps of this general type can be grounded through thesupporting panel. Sockets for these lamps can be made of metalrelatively cheaply and are satisfactory, but others have to employ areturn circuit which is insulated from the ground metal of the car. Asis well known, lamp sockets for supporting indicating lamps of thischaracter generally have an insulated wire entering the end of thesocket opposite to that in which the lamp is mounted, which is insulatedfrom the socket and terminates in a button contact which engages the endof the lamp bulb. The return circuit is through the side of the lampbase to the socket in which the lamp is held. If the return to ground isthrough the supporting panel, the socket is mounted directly in thepanel and is in metallic contact therewith.

On the other hand, if the return circuit must be insulated from thepanel, complications arise because it be comes necessary, if metal lampsockets are employed, to provide an outer housing for supporting thelamp, which is mounted in the supporting panel and in metallic contacttherewith, but is insulated from the lamp socket itself, which ispositioned within the outer housing. Where a construction of this kindis required, the cost is much more than that of the standard socketwhich is grounded through the support, and cost becomes an item of majorconsideration.

It is, therefore, the primary object of the present invention to providea lamp socket for an indicating light which can be readily supported infixed position in a metal supporting panel, but in which the returncircuit is insulated from said panel, which is of durable constructionand which can be manufactured at relatively low cost.

It is an additional object of the invention to provide a lamp socket ofthe character referred to in which the lamp is grounded through thesupporting panel but not through the lamp socket itself, whichis ofdurable construction but can be made at low cost.

These objects are accomplished according to the present invention by theprovision of a lamp socket formed of nylon, Bakelite or some othersuitable hard plastic which is, itself, supported directly in the metalinstrument panel and insulates the lamp bulb from the panel. This socketis provided with resilient fingers which snap into an opening in thesupporting panel and hold the socket in position in the opening, saidsocket having a plurality of chambers formed therein into whichconductors extend and which receive terminals that contact,respectively, the end and side of the base of the lampbulb.

Further objects and advantages of the present invention will be apparentfrom the following descriptionrefcrence being had to the accompanyingdrawings wherein 2,741,747 Patented Apr. 10, 1956 Figure 1 is anelevation of a socket constructed in accordance with the presentinvention, showing the light bulb in position and one of the conductors;

Figure 2 is a section on the line 2-2 of Figure 1;

Figure 3 is an elevation of the lamp socket of Figure I seen from theright in Figure 1; L

Figure 4 is an elevation of the lamp socket of Figure 1 seen from theleft; V

Figure 5 is a detail view of the terminal used on one of the conductorsassociated with the lamp socket;

' Figure 6 is a view similar to Figure l of a modified form of theinvention; and I Figure 7 is a detail view of a conducting member usedwith the device shown in Figure 6.

As shown in the drawings, the supporting instrument panel is designated2 and has an opening 4 in which the lamp socket is supported. The sockethas a body portion 6 from which a flange 8 integral therewith projectsand when the socket is in assembled position, the flange engages therear face of the panel 2. Also integral with the body portion 6 andextending through the opening when the socket is mounted in itssupporting panel are resilient fingers 10. These fingers are arcuate inform, as shown in Fig. 3, and while four are shown in such figure, theremay be a larger or smaller number. Such fingers are inwardly taperedadjacent the ends, as indicated at 12 and are slightly outwardly taperedadjacent the supporting panel as indicated at 14. The inward taper ofthe fingers is provided to facilitate insertion in the opening 4 and theoutward taper 14- is eifective to retain the socket in position afterinsertion in such open- 1ng.

At the right end of the socket, as shown in Fig. 2 is a relatively largechamber 16 in which the associated light bulb is positioned. The bulbhas the usual cylindrical base 18, generally of brass, which constitutesone contact, and a second contact 2!) of conventional type is mounted onthe end of the base 18, but separated therefrom by insulating material22. As more fully described later, the contact 20 is engaged by aterminal on a conductor extending to some suitable source of current andthe :base 18 is engaged bya terminal on a second conductor which formsthe returncircuit from the lamp to the current source.

In the wall of the body portion 6' of the socket is a bayonet slot 24having an axial portion 26 and a transverse portion 28 which is adaptedto be engaged by a pin or lug 30 extending from the base 18 to retainthe lamp in proper position in the socket, in the conventional manner.

Connecting with the chamber 16 is a passage 32 of smaller diameter thansaid chamber, having a tapered opening 34 of still smaller size at theend thereof, through which one of the conductors of the lamp circuitextends. This conductor includes a wire 36 having a button terminal 38secured thereto by crimping, or in any other suitable way, and a cover49 of any suitable insulating material around the wire. The. taperedopening 3% is of such size that the insulated conductor fits looselytherein so that it can be easily inserted in the socket. Positioned inthe passage 32 and surrounding the conductor is a helical spring 42, oneend of which engages the terminal 38 while the other end engages ashoulder 44 formed at the junction of the passage 32 and the taperedopening 34. Such spring holds the terminal 38 in engagement with thecontact 20 with considerable pressure so as to insure a good contact.

Formed in the socket at the lower side thereof, as

3 shown in Fig. 2, is a chamber or passage designated generally by thereference numeral 50. The shape of this chamber is best shown in Figs. 3and 4. Its inner face 52 is fiat and this face terminates at a pointabout midway of the length of the chambersothat from that point to theright, as seen in Fig. 2, the chamber 50 merges with the chamber 16 sothat there 'is no dividing wall between the two chambers but, instead,anopening is provided through which contact is made between the base 18and a terminal which is adapted to be received in the chamber 50. Thewall of the chamber opposite'the surface 50 is a curved surface 54 andextending to the right and left from the chamber 50, as seen in Fig. 3,are two slots 56 and 58, respectively, which are provided for a purposemore fully explained later. At the left end of the surface 52, ashoulder 60 .is formed while at the right end of slot 58, as seen inFig. 2, such slot is enlarged to form a shoulder 62 for a purposespecified later.

As already stated, a terminal attached to the return conductor isadapted to be received in the chamber 50, and this terminal, as a whole,is designated 59.: This conductor comprises a wire 64, covered bysuitable insulation 66. The terminal clip is best shown in Figs. 3and'S, is formed preferably of brass and the main portion of theterminal at the right of Fig. has a somewhat U-shaped cross-section asindicated at 68, with projecting wings or flanges 70 and 72 which engagethe slots 56 and 58, respectively, when the terminal is positioned inthe chamber 50. Ears 74 are crimped around the insulation 66 and ears 76are crimped around a bare part of the wire 64 itself, which extendsbeyond the end of the insulation. A tang 78 is punched out of the wing72 and bent downwardly, as seen in Fig. 2, to engage the shoulder 62 andhold the terminal clip in position in the lamp socket after it has beeninserted in the chamber 50, while a tang 80 bent upwardly from theterminal stops its movement to the right when it reaches the properposiu'on in said chamber. In other words, these two tangs 78 and 80retain the terminal in its proper position in chamber 50, as shown inFig. 2. i

The terminal 59 has a bayonet slot 82 which is engaged by a lug 84projecting from the base 18 at a point diametrically opposite the lug30. This slot is so formed that a part of the side wall of the U-shapedportion of the terminal is cut away, as indicated at 86, so that as thelamp is rotated to engage the lug 30 with the transverse part 28 of thebayonet slot 24, the lug 84 can pass into the slot 82 through thiscut-away portion of the side wall of terminal 59. The slot is alsoprovided with a curved surface 88 which is engaged by lug 84 when thelamp is rotated to its proper position and the lug 30 engages the notch90'formed in one side of the slot 24 in the pastic lamp socket.

When in such position, current can pass to the lamp through conductor36, terminal 38 and contact 20, and thence to the current source throughthe return circuit comprising lug 84, terminal 59 and the conductor 64,while the lamp is completely insulated from the panel 2 by means of theplastic lamp socket in which the lamp is mounted so that there is nocontact between any part of the lamp and such supporting panel.

In the modified form of the invention shown in Figs. 6 and 7 theconstruction of all the elements is the same as that previouslydescribed except the return circuit. Instead of having a secondconductor leading back to the source of current, the lamp is groundeddirectly through the supporting panel 2 in which the plastic lamp socketis mounted in the manner previously described. In this form of thedevice, no conductor comparable to 64 extends into the chamber 50 but,instead, there is positioned therein a conducting element which is ofsomewhat the same construction as the terminal clip 59 and electricallyconnects the base 18 of the lamp directly with the panel 2. Thisconducting element, which is designated generally by the referencenumber 109, has a U-shaped body part 68, wings or flanges of the sameform as 70 and 72 which engage slots of the same form as 56 and 58 previously described. The element 100 also has tangs 78 and 89 which engage,respectively, shoulders 62 and 69 to hold the element 104 in properposition. It is also provided with a bayonet slot 82 of the same form asthat previously described and through which the lug 84 extends when thelamp is properly positioned. Indeed, the only difference between thecontact element 100 and the terminal clip 5) resides in the omission ofthe ears 74 and 76 by means of which the terminal 59 is attached to theconductor and the addition of a contact finger which engages the panel 2to establish electrical connection between the lug 84 and the panel.This finger is indicated at 102 and is a spring finger, preferably ofbrass, which is integral with the element 100 and which extends to theright in Fig. 6, and is curved outwardly so as to engage the panel 2when properly positioned in chamber 50. The lug 84 engages the edge ofthe bayonet slot 82 so that the member 100 establishes electricalconnection between the base 18 of the lamp and panel 2. This moldedplastic socket with the conducting element 109 is equally efficient andmuch cheaper to make than the metal socket conventionally employed withindicating lamps which are grounded through the supporting instrumentpanel.

While the embodiment of the present invention as herein disclosedconstitutes a preferred form, it is to be understood that other formsmight be adopted.

What is claimed is as follows:

1. An electric lamp socket formed of suitable insulating material havinga chamber formed therein adapted to receive the base of an electriclight bulb, resilient fingers extending axially therefrom and adapted toengage an opening formed in a supporting panel for retaining said socketin position on the panel, a second chamber in said socket arrangedaxially with reference to said first chamber and communicating therewithwhich is adapted to receive a conductor having a terminal on the endthereof for engagement with a contact formed on the end of said lightbulb base, and a third chamber in said socket in substantially parallelrelation to said first chamber and having a first opening communicatingwith said first chamher and a second opening in one end thereof adaptedto receive a terminal connected to a second conductor, said terminalbeing adapted to engage the side of the light bulb base through saidfirst opening when the terminal is positioned in said third chamber.

2. An electric lamp socket formed of suitable insulating material havinga chamber formed therein to receive the base of an electric light bulbhaving a contact formed on the end of said base and a second contactprojecting from the side of said base, resilient fingers of insulatingmaterial extending axially from said socket and adapted to engage anopening formed in a supporting panel for retaining said socket inposition on said panel, a second chamber in said socket arranged axiallywith respect to said first chamber and communicating therewith, saidchamber being adapted to receive a conductor having an enlarged terminalon the end thereof and a spring for holding said terminal in engagementwith the first-mentioned contact, and a third chamber in said socket insubstantially parallel relation to said first chamber and having a firstopening communicating with said first chamber into which saidsecond-mentioned contact projects when the light bulb is positioned inthe socket, said third chamber having a second opening in one endthereof adapted to receive a terminal connected to a second conductor,said terminal being adapted to engage said second contact when theterminal is positioned in said chamber.

3. An electric lamp socket formed of suitable insulating material havinga chamber formed therein to receive the base of an electric light bulbhaving a contact formed on the end of said base and a second contactprojecting from the side of said base, resilientfingers of insulatingmaterial extending axially from said socket and adapted to engage anopening formed in a supporting panel for retaining said socket inposition on said panel, a second chamber in said socket arranged axiallywith respect to said first chamber and communicating therewith, saidchamber being adapted to receive a conductor having an enlarged terminalon the end thereof and a spring for holding said terminal in engagementwith the first-mentioned contact, a third chamber in said socket insubstantially parallel relation to said first chamber and having a firstopening communicating with said first chamber into which said secondcontact projects When the light bulb is positioned in the socket, saidthird chamber having a second opening in one end thereof adapted toreceive a terminal provided with a projecting tang and engageable withthe second contact when the terminal is positioned in said chamber, anda shoulder formed in the wall of said third chamber to hold the secondterminal in contacting position.

4. An electric lamp socket formed of suitable insulating material havinga chamber formed therein provided with a lamp retaining slot in the wallthereof and adapted to receive the base of an electric light bulb havingcontacts formed on the end and side thereof, and a lug projecting fromthe side of said base and engageable with said slot to hold the bulb inposition in said base, resilient fingers of insulating materialextending axially from said socket and adapted to engage an openingformed in a supporting panel for retaining said socket in position onsaid panel, a second chamber in said socket arranged axially withrespect to said first chamber and communicating therewith, said chamberbeing adapted to receive a conductor having an enalrged terminal on theend thereof and a spring for holding said terminal in engagement withthe first-mentioned contact, a third chamber in said socket insubstantially parallel relation to said first chamber and having a firstopening communicating with said first chamber into which said secondcontact projects when the light bulb is positioned in the socket, saidthird chamber having a second opening in one end thereof adapted toreceive a terminal provided with a projecting tang and engageable withthe second contact when the terminal is positioned in said chamber, anda shoulder formed in the wall of said third chamber to hold the secondterminal in contac ting position.

5. An electric lamp socket formed of suitable insulating material havinga chamber formed therein adapted to receive the base of an electriclight bulb, resilient fingers extending axially therefrom and adapted toengage an opening formed in a supporting panel for retaining said socketin position on the panel, a second chamber in said socket arrangedaxially with reference to said first chambar and communicatingtherewith, said second chamber being of lesser diameter than the firstchamber but large enough to receive a terminal secured to an electricalconductor, a passage through which the conductor is adapted to extendand of smaller size than the second chamber so as to form a shoulder atthe junction of said passage and a chamber, said shoulder beingengageable by one end of a spring adapted to be positioned between saidshoulder and the terminal and effective to hold said terminal inengagement with the end of the light bulb base, and a third chamber insaid socket in substantially parallel relation to said first chamber andhaving an opening communicating with said first chamber, said thirdchamber being adapted to receive a terminal effective to engage the sideof the light bulb through said opening connecting the first and thirdchambers, when the terminal is positioned in said third chamber.

6. In combination, an electric lamp socket formed of suitable insulatingmaterial having a chamber formed therein, an electric light bulb havinga base received in said chamber when the bulb is supported in thesocket, means for retaining the bulb in position in said socket,

resilient fingers extending axially from the socket and adapted toengage an opening formed in a supporting panel for retaining said socketin position on the panel, a second chamber in said socket arrangedaxially with reference to the first chamber and communicating therewith,a conductor extending into said second chamber, a terminal secured tothe end thereof and positioned within said second chamber, a spring insaid second chamber for holding said terminal in engagement with the endof the light bulb base, a third chamber in said socket substantiallyparallel with the first chamber and having a first opening communicatingtherewith, a second conductor extending into said third chamber througha second opening in one end thereof, a terminal secured to said secondconductor and positioned in said third chamber in electrical contactwith the side of the light bulb base through said first opening.

7. In combination, an electric lamp socket formed of suitable insulatingmaterial having a chamber formed therein, an electric light bulb havinga base received in said chamber when the bulb is supported in thesocket, means for retaining the bulb in position in said socket,resilient fingers extending axially from the socket and adapted toengage an opening formed in a supporting panel for retaining said socketin position on the panel, a second chamber in said socket arrangedaxially with reference to the first chamber and communicating therewith,a passage connecting with said second chamber and of smaller size thansaid chamber whereby a shoulder is formed at the junction of saidpassage and the second chamber, a conductor extending through saidpassage and into said chamber, a terminal secured to said conductor andpositioned in said second chamber, a flange on said terminal of greaterdiameter than said passage, a spring positioned in said second chamberbetween the shoulder and flange for holding the terminal in engagementwith the end of the light bulb base, a third chamber in said socketsubstantially parallel with the first chamber, said third chamber havinga first opening in the wall thereof communicating with the first chamberand a shoulder on the wall thereof, a second conductor extending intosaid chamber through on opening in one end thereof, a terminal securedto said second conductor and positioned in said third chamber inelectrical contact with the side of the light bulb base through saidfirst opening, and means on said terminal for engaging said shoulder toretain the terminal in position in said third chamber.

8. An electric lamp socket formed of suitable insulating material havinga chamber formed therein adapted to receive the base of an electriclight bulb, resilient fingers extending axially therefrom and adapted toengage an opening formed in a supporting panel for retaining said socketin position on the panel, a second chamber in said socket arrangedaxially with reference to said first chamber and communicating therewithwhich is adapted to receive a conductor having a terminal on the endthereof for engagement with a contact formed on the end of said lightbulb base, and a third chamber in said socket in sub stantially parallelrelation to said first chamber and having a first opening communicatingwith said first chamber, said third chamber having a second openingadapted to receive a conducting member provided with a terminal soformed as to engage the side of the light bulb base through said firstopening and to engage the edge of the socket retaining opening in thesupporting panel when said conducting member is positioned in said thirdchamher.

9. A lamp socket, comprising, a body of electrical insulating materialhaving a cylindrical chamber portion adapted to receive the base of alamp bulb and a coaxially extending chamber portion of lesser diameterthan the first portion and contiguous with the first portion, said firstchamber portion being open ended at one end of said body and said secondchamber portion being open ended at the opposite end of said body toeffect thereby 7 a through passage through the said body, a thirdchamber portion in said body axially parallel with said first chamberportion and tangent to said first chamber portion to effect alongitudinally extending opening in said body between said first'andthird chamber portions, said third chamber portion having facing Wallportions extending parallel with each other and axially parallel withsaid first chamber portion, each of said facing wall portions having arecess therein extending longitudinally of the said third chamberportion and parallel to the recess in the facing Wall portion, said bodyhaving an axial, longitudinal slot extending inwardly thereof from theopen end of said first chamber portion and connecting with a slotdisposed transversely in said body between the first mentioned slot andthe said opening between the said first and third chamber portions.

References Cited in the file of this patent UNITED STATES PATENTS2,283,934 lorgensen May 26, 1942 2,646,477 Heterick July 21, 19512,664,458 Rapata Dec. 29, 1953 FOREIGN PATENTS 481,075 Great BritainMar. 4, 1938

